download all the neetcode vides, with proper ranking/category classification

neetcode.sh

#!/bin/bash

set -xuo pipefail

declare -A urls

urls[easy]='https://www.youtube.com/playlist?list=PLot-Xpze53lfQmTEztbgdp8ALEoydvnRQ'
urls[medium]='https://www.youtube.com/playlist?list=PLot-Xpze53lfOdF3KwpMSFEyfE77zIwiP'
urls[hard]='https://www.youtube.com/playlist?list=PLot-Xpze53letfIu9dMzIIO7na_sqvl0w'
urls[sliding_window]='https://www.youtube.com/playlist?list=PLot-Xpze53leOBgcVsJBEGrHPd_7x_koV'
urls[stack]='https://www.youtube.com/playlist?list=PLot-Xpze53lfxD6l5pAGvCD4nPvWKU8Qo'
urls[graph]='https://www.youtube.com/playlist?list=PLot-Xpze53ldBT_7QA8NVot219jFNr_GI'
urls[backtracking]='https://www.youtube.com/playlist?list=PLot-Xpze53lf5C3HSjCnyFghlW0G1HHXo'
urls[tree]='https://www.youtube.com/playlist?list=PLot-Xpze53ldg4pN6PfzoJY7KsKcxF1jg'
urls[binary_search]='https://www.youtube.com/playlist?list=PLot-Xpze53leNZQd0iINpD-MAhMOMzWvO'
urls[linked_list]='https://www.youtube.com/playlist?list=PLot-Xpze53leU0Ec0VkBhnf4npMRFiNcB'
urls[dynamic_programming]='https://www.youtube.com/playlist?list=PLot-Xpze53lcvx_tjrr_m2lgD2NsRHlNO'

is_downloaded() {
	local needles
	local id
	id="${1##*=}"
	needles="$(find . -name '*\['"${id}"'\]*')"
	[[ ${needles} != "" ]]
	return $?
}
get_ranking() {
	grep -q "$1" easy.txt && echo "easy" && return
	grep -q "$1" medium.txt && echo "medium" && return
	grep -q "$1" hard.txt && echo "hard" && return
	echo "unranked"
}
get_playlist() { yt-dlp --print webpage_url --flat-playlist "$1"; }
get_video() { yt-dlp -S tbr -f 'worstvideo[height>360]+worstaudio[tbr!=none]' "$1"; }

# -------------------------------

for category in "${!urls[@]}"; do
	filename="${category}.txt"
	[[ -f ${filename} ]] && continue
	get_playlist "${urls[$category]}" | tee "${filename}"
done

mkdir -p easy medium hard unranked
for category in "${!urls[@]}"; do
	[[ ${category} =~ easy|medium|hard ]] &&
		continue
	mkdir -p {easy,medium,hard,unranked}/"${category}"
	filename="${category}.txt"
	while read -r video_url; do
		is_downloaded "${video_url}" &&
			continue
		ranking="$(get_ranking "${video_url}")"
		cd ${ranking}/${category} || exit 1
		get_video "${video_url}"
		cd -
	done <"${filename}"
done

for category in easy medium hard; do
	filename="${category}.txt"
	while read -r video_url; do
		if ! is_downloaded "${video_url}"; then
			cd "${category}"/ || exit 1
			get_video "${video_url}"
			cd -
		fi
	done <"${filename}"
done

find . -type d -empty -delete
tree -P '*mp4|*mkv'